Introduction and Historical Significance of Cob
– Cob is an unbaked clay or mud material used in construction.
– It has been used for centuries in various cultures around the world.
– Cob is known for its sustainability and low environmental impact.
– It is a versatile material that can be used for walls, floors, and roofs.
– Cob structures have excellent thermal properties, providing natural insulation.
– Cob has a long history, dating back to ancient civilizations.
– It was commonly used in African architecture, showcasing its durability.
– Cob buildings can be found in Wales, showcasing the material’s longevity.
– Many cob cottages in New Zealand are listed as historic places.
– Cob has been used in Afghanistan, highlighting its local availability.
Construction Techniques and Benefits of Cob
– Cob is typically made by mixing clay soil, sand, and straw.
– The mixture is then sculpted and compacted to form solid walls.
– The use of cob reduces the need for energy-intensive materials like bricks.
– Cob structures have high thermal mass, regulating indoor temperatures.
– The material is fire-resistant and has good acoustic properties.
Modern Applications of Cob
– Cob is experiencing a resurgence in sustainable and alternative building methods.
– It is used in eco-friendly construction projects around the world.
– Cob structures can be found in residential, commercial, and community settings.
– The material is often combined with other natural building techniques.
– Cob buildings can be designed to meet modern building regulations.
Cob Building Code
– In 2019, an appendix for the International Residential Code (IRC) was approved for the use of cob in load-bearing walls of single-story residential structures.
– The appendix sets limitations on the use of cob without engineering approval, considering factors like seismic activity.
Related Building Methods and Resources
– Adobe, appropriate technology, and earthbag construction are related building methods.
– Chirpici and compressed earth block are similar earth-based building materials.
– Mudbrick and rammed earth are other construction materials made from earth.
– Straw-bale construction and superadobe are alternative building methods.
– Vernacular architecture is an architectural approach based on local needs and materials.
– Resources for further reading include books like ‘Building With Cob, A Step by Step Guide’ and ‘The Hand-Sculpted House: A Philosophical and Practical Guide to Building a Cob Cottage’. Additional resources and information can be found on various websites and publications. Source: https://en.wikipedia.org/wiki/Cob_(material)
Cob, cobb, or clom (in Wales) is a natural building material made from subsoil, water, fibrous organic material (typically straw), and sometimes lime. The contents of subsoil vary, and if it does not contain the right mixture, it can be modified with sand or clay. Cob is fireproof, resistant to seismic activity, and uses low-cost materials, although it is very labour intensive. It can be used to create artistic and sculptural forms, and its use has been revived in recent years by the natural building and sustainability movements.
In technical building and engineering documents, such as the Uniform Building Code of the western USA, cob may be referred to as "unburned clay masonry," when used in a structural context. It may also be referred to as "aggregate" in non-structural contexts, such as "clay and sand aggregate," or more simply "organic aggregate," such as where cob is a filler between post and beam construction.
